sr.ht/py3-asyncpg: update to 0.20.0

sr.ht/py3-arrow: update to 0.15.4

sr.ht/py3-anyjson: bump pkgrel

sr.ht/py3-ansi2html: bump pkgrel

sr.ht/py3-alembic: upgrade to 1.3.2

sr.ht/py3-aiosmtpd: bump pkgrel

build.yml: use alpine 3.11

sr.ht/py3-importlib-metadata: add addl. dependencies

sr.ht/py3-contextlib2: new aport

sr.ht/py3-zipp: new aport

sr.ht/py3-amqp: upgrade to 2.5.2

py3-importlib-metadata: add py3-packaging to checkdepends

sr.ht/py3-celery: add importlib-metadata dependency

sr.ht/py3-importlib-metadata: new aport

sr.ht/py3-billiard: upgrade to 3.6.1.0

sr.ht/py3-kombu: upgrade to 4.6.7

sr.ht/py3-celery: upgrade to 4.4.0

sr.ht/py3-emailthreads: upgrade to 0.1.2

py3-srht: drop py3-flask-login dependency

Normalize prometheus packages